World's Tallest Buildings

Chicago became home to the world's tallest building in 1973 when the Sears Tower was topped off. The Sears Tower remained the tallest building in the world until February 13, 1996. The Sears Tower continues to be the tallest building in North America.

On July 10, 1997, the Council on Tall Buildings and Urban Habitat met in Chicago to announce new standards with four categories for measuring tall buildings. These categories are:

Height to the structural or architectural top.
Height to the highest occupied floor.
Height to the top of the roof.
Height to the top of antenna.

The Sears Tower leads in the second and third categories. The height to the top of the roof is 1,450 feet and the height to the highest occupied floor is 1,431. The twin Petronas Towers in Malaysia win the first category with its 111-foot decorative spires..

Sitting on two city blocks and rising one quarter mile (1,454 feet) above the ground, the Tower's 110 stories comprise some 4.5 million gross square feet of office and commercial space. It was designed by the architectural firm of Skidmore, Owings and Merrill, and was constructed in a little less than two and half years.

Source: Chicago Sun-Times, 10 July 1997, p32.